3. Adult Reconstruction (Hip & Knee) MCQs

A patient presents 4 weeks post-TKA with acute onset of severe knee pain, erythema, and swelling. Synovial fluid aspiration shows 45,000 WBC/uL with 95% neutrophils. Which of the following is the most appropriate initial surgical management?

Which of the following implant design factors most significantly increases the risk of mechanically assisted crevice corrosion (trunnionosis) in a total hip arthroplasty?

A patient who underwent a posterior-stabilized TKA one year ago complains of a painful "pop" when actively extending the knee from a flexed position. What is the most likely etiology of this symptom?

A 65-year-old woman undergoes a total hip arthroplasty through a posterior approach. Postoperatively, she experiences recurrent posterior dislocations. Radiographs show the acetabular component is placed in 30 degrees of abduction and 5 degrees of retroversion. What is the primary cause of her posterior instability?

During a posterior-stabilized total knee arthroplasty, the posterior cruciate ligament is resected to accommodate the implant box. Which vascular structure is most directly at risk of injury during this specific step and frequently requires electrocautery?

A 68-year-old woman presents with a painful catching sensation in her knee 9 months after a posterior-stabilized total knee arthroplasty. The catching occurs as she actively extends her knee from a flexed position, specifically around 30 to 40 degrees of flexion. What is the most likely etiology?

A 55-year-old man undergoes a total hip arthroplasty using a ceramic-on-ceramic bearing. Two years postoperatively, he complains of a loud, audible squeaking sound from his hip when walking. Which of the following factors is most strongly associated with this phenomenon?

A 70-year-old man presents with a painful, swollen total knee arthroplasty 4 years after the index surgery. Radiographs show no component loosening. Aspiration of the knee yields synovial fluid with a white blood cell count of 15,000 cells/µL and 85% polymorphonuclear neutrophils. What is the most appropriate next step in management?

Following a total hip arthroplasty, the patient complains that the operative leg feels too long. Postoperative radiographs reveal the center of rotation of the femoral head is superior to the tip of the greater trochanter, and the teardrop-to-lesser trochanter distance is increased by 15 mm compared to the contralateral side. Which intraoperative adjustment would have best prevented this?

Polyethylene wear in total knee arthroplasty (TKA) often differs from that in total hip arthroplasty. Which of the following best describes the predominant wear mechanism that led to failure in historical flat-on-flat (non-conforming) TKA polyethylene inserts?

In a normal knee, femoral rollback refers to the posterior translation of the femoral contact point on the tibia during deep flexion. In a cruciate-retaining total knee arthroplasty, which of the following is essential to achieve appropriate femoral rollback?

During a primary total knee arthroplasty, the surgeon evaluates the flexion and extension gaps. The extension gap is symmetric and perfectly balanced, but the flexion gap is excessively tight. Which of the following maneuvers is the most appropriate to address this specific mismatch?

A 62-year-old man presents with groin pain and swelling 5 years after a primary metal-on-polyethylene total hip arthroplasty. MRI with metal artifact reduction shows a solid periprosthetic pseudotumor. Aspiration yields negative cultures. Which of the following implant factors is most strongly associated with this condition?

During a primary total knee arthroplasty for severe varus osteoarthritis, the surgeon inadvertently transects the superficial medial collateral ligament (MCL) at its mid-substance. Which of the following is the most appropriate intraoperative management?

A 58-year-old woman with a documented history of severe, blistering skin reactions to cheap jewelry is scheduled for a total knee arthroplasty. What is the most common metal sensitizer in orthopedic implants, and what is the most appropriate alternative implant choice for her?

A 75-year-old woman with a history of a long-segment lumbar spinal fusion (L2 to the sacrum) is undergoing a primary total hip arthroplasty. How does her spinal fusion alter her spinopelvic kinematics when moving from a standing to a seated position, and how should cup positioning be adjusted?

During a total knee arthroplasty, the surgeon uses trial components to assess ligamentous balancing. The extension gap is found to be symmetric and well-balanced, but the flexion gap is excessively tight both medially and laterally. Which of the following is the most appropriate surgical step to achieve a balanced knee?

A 68-year-old man presents with insidious onset of pain 3 years after a total hip arthroplasty. Laboratory evaluation shows an ESR of 45 mm/hr and a CRP of 18 mg/L. Joint aspiration yields a white blood cell count of 4,800 cells/uL with 88% neutrophils. Based on current consensus guidelines, what is the most appropriate definitive management?